Let-off mechanism for looms.



No. 744,941. PATENTED NOV. 24, 1903.

- C. F. ROPER.

LET-OPP MECHANISM FOR LOOMS.

APPLIOATION FILED SEPT. 9, 190a. No MODEL. z SHEETS-SHEET 1.

. No. 744,941. PATENTED NOV. 24, 1903.

O. P. ROPBR.

LET-OFF MECHANISM FOR LOOMS;

APPLICATION FILED SEPT. a, 1903. N0 MODEL. 2 SHEETS-SHEET z.

Ito 744,941.

ITIED Patented November 24, 1908.

PATENT OFF CHARLES F. ROPER, OF HOPEDALE, MASSACHUSETTS, ASSIGNOR TO DRAPER COMPANY, OF HOPEDALE, MASSACHUSETTS, A CORPORATION OF MAINE.

LET OFF MECHANISM FOR LOOMS.

SPECIFICATION forming part of Letters Patent No. 744,941, dated November 24:, 1903.

Application filed September 8, 1908. Serial No. 172,820. (No model.)

To (LZZ whom it may concern/.-

Be it known that 1, CHARLES F. Rornn, a citizen of the United States, residing at Hopedale,county of WVorcestenand State of Massachusetts, have invented an Improvement in Let-Off Mechanism for Looms, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing IO like parts.

In the let-off mechanism forming the subject matter of United States Patent No. 647,815 the warp-beam is positively rotated by means including a pawl and ratchet, both the warp tension and the diameter of the yarn mass on the beam governing the angular movement or advance of the ratchet at each stroke of the pawl. The beam is provided with a large gear in mesh with a pinion fast on a driving-shaft, on which latter the ratchet is rotatably mounted, and a very simple speed-reducing gearing is shown intermediate the ratchet and the shaft to rotate the latter at a very slow rate of speed, as is 2 5 necessary. Said speed-reducing gearing comprises an annular internal gear fast on the shaft in mesh with a non-'rotatable gear having a less number of teeth and mounted loosely and eccentrically on the ratchet, a radial arm being rigidly secured to or forming a part of the non-rotatable gear and having a slight longitudinal and rocking movement. Owing to the difference in the number of teeth of the two gears, the internal gear will 3 5 fall back or rotate more slowly than the movement of the non-rotatable gear as it travels along the internal gear, due to its circular movement, and thus the speed of the pinionshaft is reduced. In practice it was noticed 40 that there was a peculiar unevenness" in the let-off, the warp-beam slowing down and then increasing its speed at regular intervals entirely independent of the warp tension or the diameter of the yarn mass on the beam. This 5 unevenness was not noticeable in a large number of fabrics; butin some of the lighter qualities'it caused objectionable streaks in the cloth. In the course of my experiments I discovered that this peculiarity was due to the fact that the arm rigidly secured to the external non-rotatable gear caused a retardation. the circular movement of said gear at one time and with it at another time, so that at the former time the rotat-ive speed of the intion of said gear when said arm rocked in one direction and an acceleration of its movement When the arm rocked in the other direc- In other words, the arm moved against ternal gear (and consequently of the warpbeam) slowed down, while at the latter time the speed of the internal gear was increased. My present invention has for its object the production of let-off mechanism of the type shown in said patent, but which is free from the objection hereinbefore explained,tl1e particular novelty of my invention residing especially in the speed-reducing gearing, and by' the construct-ion to be hereinafter described the objection stated is completely obviated and the rate of let-off is governed entirely by the warp tension and the diameter ,of the yarn mass on the beam.

and Fig. 3 is an enlarged inner side view of the two speed-reducing gears and the means for preventing rotation of one of them, the pinion-shaft being omitted.

The warp-beam B,having an attached large gear B, and the whip-roll "W, mounted in rocking arms W, the rocker-arm W con-'85 nected therewith and provided with a rocking stud 'w to which is secured a rod or link at, having fast upon it a collar a the fixed ear b, through which the link passes loosely, the tension-spring S, the member 0 of the compound pawl-carrier fulcrumed at c and pivotally connected at a with the link a, the other member at of said pawl-carrier loosely mounted on the driving-shaft B carrying a pinion B (see dotted lines, Fig. 1,) in mesh with the beam-gear B and having loosely mounted upon it the ratchet B with which cooperates the let off pawl (1 may be and are all substantially as in the patent referred to and operate as therein provided. So, too, the depending arm 01 (see dotted lines, Fig. 2,) rigidly connected with the hub of the member d,'the rock-shaft E, extended beyond it and having fast upon it the upturned arm E to engage the periphery of the yarn mass on the beam, the second arm E? on said rockshaft pivotally connected at c, Fig. 2, with the lower end of an upturned radius-bar E the upper end passing between the members and d. of the pawl-carrier and being provided with a transverse stud e to enter longitudinal guideways in said members, are all substantially as in said patent.

Herein a link at is pivotally connected with the free end of arm (1 and at its forward end said link has an elongated eye (1 to receive a pin d on the lay-sword A the forward beat of the lay moving the link in the direction of arrow 5, Fig. 1, to impart the feed-stroke to the pawl d its starting-point varying according to the warp tension and diameter of the yarn mass, as will be understood.

The ratchet B is loosely mounted on the driving or pinion shaft B the latter having fast upon it the hub g of an annular internal gear g, meshing with an external gear g, having a less number of teeth.

The hub of the gear g is loosely mounted on an eccentric g secured to the ratchet B and two lateral and diametrically opposite lugs are formed on the inner side of gear g for a purpose to be described.

A concentric hub g on the ratchet surrounds the shaft B between the ratchet and centric g and the ratchet, said arm having a longitudinal slot 9 in its free end to embrace the rock-shaft E, permitting longitudinal movement of said arm.

As clearly shown in Fig. 3, the head G has an elongated longitudinal opening g which loosely embraces the concentric hub 9 so that the arm g may move longitudinally a limited distance supported by said hub and the rock-shaft E, but having no lateral or rocking movement. The head is provided with oppositely-extended elongated ears 9, each provided with a slot at right angles to the longitudinal axis of the arm g said slots being in alinement and receiving with a sliding fit the lugs 20 on the gear g.

By the construction just described rotation of the ratchet in the direction of arrow 25, Fig. 3, imparts a circular movement to the gear g, its rotation being prevented by the arm g and said gear travels along the internal gear g, rotating the latter in the same direction, but at a reduced speed, owing to the difference in the number of teeth of the two gears. The arm g has a movable or sliding connection with the gear g and effectually prevents rotation thereof; but by virtue of such movable connection the arm movable longitudinally only has no effect whatever upon the circular movement of the gear due to the eccentric g Consequently the objectionable retardation and acceleration of the rotative speed of the gear g, and thereby of the warp-beam, is entirely obviated and the let-off is affected only by variations in warp tension and in the diameter of the yarn mass on the beam.

A friction-clamp, as F, Figs. 1 and 2, may be used, if desired, cooperating with a concentric hub or disk on the ratchet, asin the patent herein before referred to.

My invention is not restricted to the precise construction and arrangement herein shown and described, as the same may be varied or modified in different particulars by those skilled in the art without departing from the spirit and scope of my invention.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a loom, the warp-beam, a shaft having a ratchet loose thereon, transmitting means between the shaft and warp-beam to effect rotation of the latter, speed-reducing gearing intermediate the ratchet and shaft to rotate said shaft, one member of said gearing being fast on the latter and the other member being mounted loosely and eccentrically on the ratchet, and means connected with and movable relatively to the latter of said members to prevent its rotation.

2. In a loom, the warp-beam having an attached gear, a pinion in mesh therewith, a pinion-shaft, a ratchet loose thereon, speedreducing gearing intermediate the ratchet and the shaft, one member of said gearing being fast on the shaft and the other member being mounted loosely and eccentrically on the ratchet, and means movably connected with said latter member, to prevent its rotation.

3. In a loom, the warp-beam, a shaft having a ratchet loose thereon, transmitting means between the shaft and warp-beam to effect rotation of the latter, speed-reducing gearing intermediate the ratchet and shaft to rotate said shaft, said gearing comprising an external gear mounted loosely and eccentrically on the ratchet, an annular internal gear in mesh therewith and fast on the shaft, and means connected with and movable relatively to the external gear to prevent its rotation.

4. In a loom, the warp-beam, a shaft having a ratchet loose thereon, transmitting means between the shaft and warp-beam to effect rotation of the latter, speed-reducing gearing intermediate the ratchet and shaft to rotate said shaft, said gearing comprising an external gear mounted loosely and eccentrically on the ratchet, an annular internal gear in mesh therewith and fast on the shaft, and an arm movably connected with the external gear to prevent its rotation and itself capable of longitudinal movement only.

5. In let-ofi mechanism for looms, a ratchet having an attached eccentric and a concentric hub, an external, non rotatable gear mounted loosely on the eccentric and provided with diametrically opposite, lateral lugs on one side, a driving-shaft on which the ratchet is rotatably mounted, an internal gear fast on the shaft and in mesh with the external gear, the latter having the smaller number of teeth, whereby rotation of the ratchet effects rotation of the shaft at a reduced speed, means to actuate the ratchet, and a longitudinallymovable arm having a yoke-like head to embrace the concentric hub of the ratchet and provided with slots at right angles to its length to receive thelugs on the external gear, to prevent rotation thereof.

6. In let-off mechanism for looms, a ratchet having an attached eccentric, an external, non-rotatable gear mounted loosely thereon, a driving-shaft on which the ratchet is rotaname to this specification in the presence of two subscribing witnesses.

CHARLES F. ROPER. Witnesses:

GEORGE OTIS DRAPER, ERNEST W. Wow. 

